1. Field of the Invention
The present invention relates to a structure of an upper rotating body of a construction machine such as a hydraulic excavator.
2. Description of the Related Art
There is a known construction machine provided with an upper rotating body rotatably mounted on a lower travelling body.
The upper rotating body is provided with a working attachment which is supported by a pair of left and right vertical plates disposed on a rotating frame so as to be raised and lowered, actuators such as a boom cylinder and an arm cylinder disposed in the attachment, a working oil tank and a control valve disposed lateral to the vertical plates, and hydraulic pipes for coupling the control valve and the actuators.
In the above type of upper rotating body, there is sometimes a case where a retaining tool for bundling and retaining the pipes so as to prevent the hydraulic pipes from going apart from each other in accordance with an action of the attachment is attached to the vertical plates.
For example, Japanese Patent Laid-Open No. Hei11-181829 discloses a technique that efficiency for arrangement space of hydraulic pipes is improved by inserting a plurality of hydraulic pipes for coupling cylinders (actuators) for activating a working machine (working attachment) and a control valve into a space portion provided below a working oil tank.
However, as in the above Patent Document, in the case where the hydraulic pipes are arranged between the control valve and the retaining tool through the space portion below the working oil tank, there is a need for arranging the hydraulic pipes by once taking the hydraulic pipes through below the working oil tank and then bringing the hydraulic pipes up again to the retaining tool. Therefore, there is a problem that an arrangement route is lengthened by taking the hydraulic pipes through below the working oil tank once.
When the arrangement route is lengthened as mentioned above, pressure loss of working oil flowing through the hydraulic pipes is increased so that drive efficiency for the actuators by the working oil is decreased.